Economic survey of the United States, 1992 = Estudio económico de los Estados Unidos, 1992

Incluye Bibliografía

Estudio económico de Estados Unidos, 1993 = Economic survey of the United States, 1993

Incluye Bibliografía

Economic survey of United States, 1994 = Estudio económico de los Estados Unidos, 1994

Incluye Bibliografía

Economic survey of United States, 1995

Includes bibliography

Economic survey of United States, 1996

Includes bibliography

Economic survey of United States, 1997

Includes bibliography

Economic survey of United States, 1998

Includes bibliography

Estudio económico de los Estados Unidos, 1988 = Economic survey of the United States of America, 1988

Incluye Bibliografía

Estudio económico de los Estados Unidos, 1991 = Economic survey of the United States, 1991

Incluye Bibliografía

The United States and Latin America and the Caribbean: highlights of economy and trade

Document prepared on the occasion of the visit of President Barack Obama to Brazil, Chile and El Salvador in March 2011

Nutrient enrichment is related to two facets of beta diversity for stream invertebrates across the united states

Beta diversity, the spatial or temporal variability of species composition, is a key concept in community ecology. However, our ability to predict the relative importance of the main drivers of beta diversity (e. g., environmental heterogeneity, dispersal limitation, and environmental productivity) remains limited. Using a comprehensive data set on stream invertebrate assemblages across the continental United States, we found a hump-shaped relationship between beta diversity and within-ecoregion nutrient concentrations. Within-ecoregion compositional dissimilarity matrices were mainly related to environmental distances in most of the 30 ecoregions analyzed, suggesting a stronger role for species-sorting than for spatial processes. The strength of these relationships varied considerably among ecoregions, but they were unrelated to within-ecoregion environmental heterogeneity or spatial extent. Instead, we detected a negative correlation between the strength of species sorting and nutrient concentrations. We suggest that eutrophication is a major mechanism disassembling invertebrate assemblages in streams at a continental scale.

Comparison of snow data assimilation system with GPS reflectometry snow depth in the Western United States

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A Survery of Western United States Instream Flow Programs and The Policies that Protect a River's Ecosystem

The Western United States can best be described as a vast, varying land, with the high plains to the east and the jagged horizons of Rockies to the west. However there is one common trait shared by these states: the lack of water resources. With the continued development of this land, the fact that water is scarce is becoming more real. This issue became more difficult to handle as the public became more aware that many competing uses existed for the finite resource, and those different uses were degrading the natural environments of the surface waters. With this realization instream flow policies provides a comprehensive account of the policy framework a selected number of western states have established in order to protect instream flows and the overall health of a river's ecosystem. Also included is the identification of key policies that should be promoted or removed from a state's instream flow program. Ultimately, this thesis continues to add the the ever-evolving process of modernizing water law frameworks.